Reinforcement prostheses, for example prostheses for reinforcing the abdominal wall, are widely used in the surgical field. These prostheses are intended to treat hernias by temporarily or permanently filling a tissue defect. These prostheses are generally made of biocompatible prosthetic fabric, for example knits, and can have a number of shapes, for example rectangular, circular or oval, depending on the anatomical structure to which they are to be fitted.
Prosthetic fabrics such as knits are intrinsically adhesiogenic and fibrogenic, irrespective of the nature of the tissues with which they are put in contact. It is desirable to provide reinforcement prostheses that, although based on prosthetic fabric, also prevent post-surgical adhesions, especially when they are positioned intraperitoneally.
Postsurgical adhesions include all non-anatomical fibrous connections accidentally induced by a surgical act during the normal process of cicatrization. They may occur in all surgical disciplines regardless of the operation in question. Postsurgical adhesions can provoke syndromes which can be classed principally as chronic pain, occlusive syndromes and female infertility. Furthermore, they increase very substantially the risks of making errors in follow-up surgery, while prolonging the operating times, since the preliminary dissection can be very awkward in such cases.
To remedy this problem, it was suggested to render one face of these reinforcement prostheses completely smooth during the initial inflammatory phase, and therefore not favorable to the generation of adhesions. To do this, a physical barrier is interposed between the structures which are not intended to adhere to each other.
However, the desired barrier effect poses the problem of the intrinsic adhesive power of this barrier. The reason is that if the barrier is made of a non biodegradable material, it can itself be the source of adhesions over the course of time; and if it is biodegradable, its biodegradation must be sufficiently noninflammatory so as not to cause adhesions itself on one hand, and on the other hand, its biodegradation kinetics should be appropriate so as to allow the barrier to remain integrate during the time needed for it to perform its function of prevention of formation of adhesions.